Synergistic herbicide combinations and method of application

ABSTRACT

A synergistic herbicidal composition comprising a mixture of: (a) a herbicidally effective amount of 2-(2-chloro-4-methanesulfonylbenzoyl)-1,3-cyclohexanedione; and (b) a herbicidally effective amount of a compound selected from the group consisting of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine, 3-amino-2,5-dichlorobenzoic acid, and 2-chloro-N-isopropylacetanilide, and mixtures thereof; at a weight ratio of (a) to (b) of from about 0.1:1 to about 20:1.

This is a continuation of application Ser. No. 814,443, filed Dec. 30,1985, abandoned.

BACKGROUND OF THE INVENTION

The protection of crops from weeds and other vegetation which inhibitcrop growth is a constantly recurring problem in agriculture. To helpcombat this problem researchers in the field of synthetic chemistry haveproduced an extensive variety of chemicals and chemical formulationseffective in the control of such unwanted growth. Chemical herbicides ofmany types have been disclosed in the literature and a large number arein commercial use.

In some cases, active herbicides have been shown to be more effective incombination than when applied individually. The result is often termed"synergism" since the combination demonstrates a potency or activitylevel exceeding that which it would be expected to have, based on aknowledge of the individual potencies of the components. The presentinvention resides in the discovery that certain cyclohexanediones andother chemical compounds already known individually for their herbicidalpotency, display this synergism when applied in combination.

THE PRIOR ART

The compounds which can be combined to form the synergistic herbicidalcompositions of this invention are already known in the art asherbicides. One such compound is2-(2-chloro-4-methanesulfonylbenzoy)-1,3-cyclohexanedione. This compoundis disclosed in European Patent Publication No. 137,963, published4-4-85. It is also disclosed and claimed in U.S. application Ser. No.634,408. Another of the compounds used in the synergistic compositionsof the invention is2-chloro-4-(ethylamino)-6-(isopropylamino)-striazine, commonly know asAtrazine. Still another compound used in the synergistic hericidalcomposition of this invention is 3-amino-2,5-dichlorobenzoic acid,commonly known as Chloramben, described and claimed in U.S. Pat. Nos.3,014,063 and 3,174,842. Yet another compound used in the synergisticcompositions of this invention is 2-chloro-4-N-isopropylacetanilide,commonly known as Propachor.

DESCRIPTION OF THE INVENTION

It has now been discovered that synergism in the control of undesirablevegetation is exhibited by compositions comprising a mixture of thefollowing components:

(a) a herbicidally effective amount of2-(2-chloro-4-methanesulfonylbenzoyl)-1,3-cyclohexandione; and

(b) a herbicidally effective amount of a compound selected from thegroup consisting of 3-(amino-2,5-dichlorobenzoic acid,2-chloro-N-isopropylacetanilide or2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine, and mixturesthereof.

Another embodiment of this invention is a method of controllingundesirable weed pests, and this method comprises applying thesynergistic compositions of the invention to the locus where control isdesired.

The terms "synergism" and "synergistic" are used herein to convey theresult observed when a combination of herbicides demonstrates a potencyin excess of that which the combination would be expected to produce onthe basis of the potencies of each herbicide applied individually.

The term "herbicide" is used herein to denote a compound which controlsor modifies the growth of plants. The term "herbicidally effectiveamount" is used to indicate the quantity of such a compound orcombination of such compounds which is capable of producing acontrolling or modifying effect. Controlling or modifying effectsinclude all deviations from natural development, for example: killing,retardation, leaf burn, dwarfing and the like. The term "plants" is usedto include all postemergent vegetation, ranging from seedlings toestablished vegetation.

As previously mentioned, the synergistic compositions of this inventionall employ chemical compounds previously known for their herbicidalactivity. One of these compounds,2-(2-chloro-4-methanesulfonylbenzoyl)-1,3-cyclohexanedione, is disclosedin European Patent Application No. 0 137 963, published 4-4-85, and itis also disclosed and claimed in U.S. application Ser. No. 634,408.Still another compound2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine, commonly known asAtrazine, is commercially sold under various tradenames, and isdescribed in the Herbicide Handbook of the Weed Science Society ofAmerica, 5th Edition, 1983. Another of the compounds used in thesynergistic combinations of the invention, 3-amino-2,5-dichlorobenzoicacid, is commercially available under a number of tradenames and isdescribed on page 92 of the Herbicide Handbook of the Weed ScienceSociety of America, 5Edition, 1983. Yet another compound used in thesynergistic compositions of this invention is2-chloro-4-N-isopropylacetanilide, is described on pages 401 and 402 ofthe Herbicide Handbook of the Weed Science Society of America, 5thEdition, 1983.

These compounds are effectively used in the synergistic compositions ofthe invention at ratios of Compound (a) to Compound (b) as set forthabove, ranging from about 0.01:1 to about 20:1. Preferably, the ratio ofCompound (a) to Compound (b) is from about 0.1:1 to about 10:1.

HERBICIDAL TEST DATA

Synergism for the compositions of this invention was measured inaccordance with the following test:

Aluminum pans measuring 9×6×4 inches (cm) were filled with a sandy loamsoil and 6 furrows were impressed across the width of each flat. Anumber of weed species were seeded into furrows and covered with soil.Along with the seed species were two corn hybrids which were inserted todetermine the extend of damage, if any, upon plant species.

The weed species were as follows:

    ______________________________________                                        Abbreviation                                                                            Common Name    Scientific Name                                      ______________________________________                                        YNS       yellow nutsedge                                                                              Cyperus esculentus                                   PNS       purple nutsedge                                                                              Cyperus rotundus                                     RJG       rhizome johnsongrass                                                                         Sorghum halepense                                    FP        fall panicum   Panicum dichotomiflorum                              WPM       wild proso millet                                                                            Panicum milaceum                                     GG        goosegrass     Eleusine indica                                      SC        shattercane    Sorghum bicolor                                      YFT       yellow foxtail Setaria lutescens                                    GFT       green foxtail  Seteria viridis                                      PW        redroot pigweed                                                                              Amaranthus retroflexus                               AMG       annual morningglory                                                                          Ipomoea purpurea                                     SP        sicklepod      Cassia obtusifolia                                   VL        velvetleaf     Abutilon theophrasti                                 LCG       large crabgrass                                                                              Digitaria ischaemum                                  JG        johnsongrass   Sorghum halepense                                    ______________________________________                                    

The plant species were as follows:

    ______________________________________                                        CN            corn       Zea maize (L.)                                       ______________________________________                                    

Chemical solutions, which in the case of pre-emergence testing weresprayed the same day of seeding, were prepared as follows:

All compounds were of technical grade, except Prowl which was what istermed a 4E formulation, which means a 4 pound per gallon emulsionconcentrate. All of the technical grade compounds were either appliedsingly, or applied in conjunction with the synergistic herbicidalcompound, by diluting the technical grade compounds with acetone andwater at 1:1 ratio water and applying at a spray volume of 25 gal/acre.The quantity of active ingredient for each compounds which was appliedis indicated under the heading "Application Rate".

In the case of post-emergent testing, the weed and plant species wereallowed to sprout and application was made approximately 2 weeks afterplanting.

The various rates of application are indicated in the tables under"Application Rate".

Flats were then placed in a greenhouse, and watered by overheadsprinkling. Air temperatures ranged from 18° C. to 27° C. Flats werekept moist during the course of each experiment.

After treatment, each row of seedlings was visually rated for growthcontrol due to all factors of injury. In pre-emergence testing theratings were done 28 days after treatment. In post-emergent testing, therating was done 21 days after treatment. Untreated flats of seedlingswere used for comparison, zero percent injury of growth control isequivalent to growth in control flats. One hundred percent growthcontrol is equivalent to complete kill.

Herbicide interaction responses were evaluated by use of Limpel'sformula (Limpel, L. E., et al., 1962, "Weed Control byDimethyltetrachloroterephthalate Alone and in Certain Combinations,"Proc. NEWCC, 16:48-53): ##EQU1## where E=expected response

where

X=observed (O) value or percent growth control when the herbicide isapplied singly; and

Y=observed (O) value or percent growth control when the second herbicideis applied singly.

A response is synergistic when an observed value is greater than thecalculated value, a synergistic response is understood to be one inwhich the interaction response is greater than the sum of responses fromthe individual chemical treatments. An antagonistic response is theopposite situation.

In the tables which follows:

E=expected activity

O=observed activity

R=result, i.e., additive (AD), antagonistic (A) or synergistic (S)

                                      TABLE 1                                     __________________________________________________________________________    Pre-Emergence                                                                 Application  YNS      PNS      RJG    CN    CN                                Treatment                                                                            Rate lb/A                                                                           O  E  R  O  E  R  O E R  O E R O E R                             __________________________________________________________________________    X-100  1/4   85       65       0      0     0                                        1/2   90       95       30     0     0                                 ATRAZINE                                                                             1/4   0        0        0      0     0                                        1/2   0        0        0      0     0                                 LASSO  1/2   100      80       0      0     0                                        1     100      100      0      0     0                                 AMIBEN 1     0        0        30     0     15                                       2     0        65       50     70    25                                PROWL  1/4   0        0        20     0     0                                        1/2   0        0        0      50    10                                RAMROD 2     20       30       0      0     0                                        3     100      90       0      0     0                                 X-100  1/4 + 1/4                                                                           90 85 S  80 65 S  20                                                                              0 S  0 0   0 0                               +      1/2 + 1/4                                                                           95 90 S  90 95 A  30                                                                              30                                                                              AD 0 0   0 0                               ATRAZINE                                                                             1/2 + 1/2                                                                           98 95 S  95 65 S  20                                                                              0 S  0 0   0 0                                      1/2 + 1/2                                                                           95 90 S  95 95 AD 30                                                                              30                                                                              AD 0 0   0 0                               X-100  1/4 + 1/2                                                                           100                                                                              100                                                                              AD 95 93 S  15                                                                              0 S  0 0   0 0                               +      1/2 + 1/2                                                                           98 100                                                                              A  85 99 A  40                                                                              30                                                                              S  0 0   0 0                               LASSO  1/4 + 1                                                                             95 100                                                                              A  95 100                                                                              A  20                                                                              0 S  0 0   0 0                                      1/2 + 1                                                                             95 100                                                                              A  100                                                                              100                                                                              AD 60                                                                              30                                                                              S  10                                                                              0   10                                                                              0                               X-100  1/4 + 1                                                                             95 85 S  95 65 S  20                                                                              30                                                                              A  0 0   30                                                                              15                              +      1/2 + 1                                                                             98 90 S  98 95 S  50                                                                              51                                                                              A  40                                                                              0   30                                                                              15                              AMIBEN 1/4 + 2                                                                             95 85 S  95 88 S  30                                                                              50                                                                              A  25                                                                              70  40                                                                              25                                     1/2 + 2                                                                             95 90 S  98 98 AD 75                                                                              65                                                                              S  65                                                                              70  50                                                                              25                              X-100  1/4 + 1/4                                                                           95 85 S  95 65 S  10                                                                              20                                                                              A  20                                                                              0   0 0                               +      1/2 + 1/4                                                                           95 90 S  98 95 S  55                                                                              44                                                                              S  25                                                                              0   30                                                                              0                               PROWL  1/4 + 1/2                                                                           95 90 S  95 95 AD 10                                                                              0 S  40                                                                              50  20                                                                              10                                     1/2 + 1/2                                                                           95 90 S  95 95 AD 10                                                                              30                                                                              A  45                                                                              50  40                                                                              10                              X-100  1/4  + 2                                                                            95 88 S  98 76 S  5 0 S  0 0   0 0                               +      1/2 + 2                                                                             95 92 S  99 97 S  15                                                                              30                                                                              A  0 0   0 0                               RAMROD 1/4 + 3                                                                             100                                                                              100                                                                              AD 100                                                                              97 S  5 0 S  0 0   0 0                                      1/4 + 3                                                                             95 100                                                                              A  95 100                                                                              A  65                                                                              30                                                                              S  0 0   0 0                               CONTROL                                                                              --    0  0  0  0  0  0  0 0 0  0 0   0 0                               __________________________________________________________________________     X-100 = 2(2-chloro-4-methanesulfonylbenzoyl)-1,3-cyclohexanedione             Atrazine = 2chloro-4-(ethylamino)-6-isopropylamino)-s-triazine                Lasso = 2chloro-2',6diethyl-N--(methoxymethyl)acetanilide                     Amiben = 3amino-2,5-dichlorobenzoic acid                                      Prowl = N--(1ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzeneamine                Ramrod = 2chloro-N--isopropylacetanilide                                 

                                      TABLE 2                                     __________________________________________________________________________    Pre-Emergence                                                                 Application                                                                   Treat-                                                                              Rate                                                                             FP       WPM      GG       SC       YFT      GFT                     ment  lb/A                                                                             O  E  R  O  E  R  O  E  R  O  E  R  O  E  R  O  E  R                 __________________________________________________________________________    X-100 1/4                                                                              20       95       100      15       95       10                            1/2                                                                              100      100      100      95       90       65                      ATRA- 1/4                                                                              60       0        65       0        45       30                      ZINE  1/2                                                                              70       40       95       0        80       60                      LASSO 1/2                                                                              100      95       100      90       90       100                           1  100      98       100      100      90       100                     AMIBEN                                                                              1  100      95       95       0        75       45                            2  95       95       100      0        85       85                      PROWL 1/4                                                                              100      95       100      90       95       95                            1/2                                                                              100      100      100      100      100      100                     RAMROD                                                                              2  75       50       95       0        90       95                            3  100      90       100      0        98       100                     X-100 1/4+1/4                                                                          100                                                                              68 S  100                                                                              95 S  100                                                                              100                                                                              AD 100                                                                              15 S  90 97 A  100                                                                              37  S                +     1/2+1/4                                                                          100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 95 95 AD 95 94 S  100                                                                              75  S                ATRA- 1/2+1/2                                                                          95 75 S  100                                                                              97 S  100                                                                              100                                                                              AD 90 15 S  90 99 A  100                                                                              64  S                ZINE  1/2+1/2                                                                          100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              95 S  100                                                                              98 S  100                                                                              86  S                X-100 1/4+1/2                                                                          100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 90 91 A  85 99 A  100                                                                              100 AD               +     1/2+1/2                                                                          100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 93 A  100                                                                              99 S  100                                                                              100 AD               LASSO 1/4+1                                                                            100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 95 100                                                                              A  100                                                                              99 A  100                                                                              100 AD                     1/2+1                                                                            100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 100                                                                              A  100                                                                              99 S  100                                                                              100 AD               X-100 1/4+1                                                                            100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              15 S  98 99 A  100                                                                              50  S                +     1/2+1                                                                            100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 95 S  98 98 AD 100                                                                              81  S                AMIBEN                                                                              1/4+2                                                                            100                                                                              96 S  100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 70 15 S  80 99 A  100                                                                              86  S                      1/2+2                                                                            100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 95 S  95 98 A  95 95  AD               X-100 1/4+1/4                                                                          100                                                                              100                                                                              AD 98 100                                                                              A  100                                                                              100                                                                              AD 95 91 S  100                                                                              100                                                                              AD 100                                                                              95  S                +     1/2+1/4                                                                          100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 99 A  100                                                                              99 S  100                                                                              98  S                PROWL 1/4+1/2                                                                          100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 100                                                                              A  100                                                                              100                                                                              AD 100                                                                              100 AD                     1/2+1/2                                                                          100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100 AD               X-100 1/4+2                                                                            100                                                                              80 S  100                                                                              97 A  100                                                                              100                                                                              AD 90 15 S  100                                                                              99 S  100                                                                              95  S                +     1/2+2                                                                            100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              95 S  100                                                                              99 S  100                                                                              98  S                RAMROD                                                                              1/4+3                                                                            100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 65 15 S  100                                                                              100                                                                              AD 100                                                                              100 AD                     1/4+3                                                                            100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 85 95 A  100                                                                              100                                                                              AD 100                                                                              100 AD               CON-  -- 0  0  0  0  0  0  0  0  0  0  0     0  0                             TROL                                                                          __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________    Pre-Emergence                                                                 Application                                                                          Rate                                                                              PW       AMG      SP     VL       LCG      JG                      Treatment                                                                            lb/A                                                                              O  E  R  O  E  R  O  E R O  E  R  O  E  R  O  E  R                 __________________________________________________________________________    X-100  1/4 100      100      20     100      75       20                             1/2 70       100      70     100      100      95                      ATRAZINE                                                                             1/4 100      100      0      100      10       0                              1/2 100      100      55     100      10       45                      LASSO  1/2 90       0        60     65       90       100                            1   95       10       85     60       100      100                     AMIBEN 1   40       0        50     100      90       95                             2   80       0        65     100      90       98                      PROWL  1/4 70       0        0      0        80       80                             1/2 85       0        0      85       100      95                      RAMROD 2   60       0        0      0        50       75                             3   100      10       60     30       85       95                      X-100  1/4 + 1/4                                                                         100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 60 20                                                                              S 100                                                                              100                                                                              AD 100                                                                              77 S  85 20  S                +      1/2 + 1/4                                                                         100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 90 70                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 95 95  AD               ATRAZINE                                                                             1/2 + 1/2                                                                         100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 64                                                                              S 100                                                                              100                                                                              AD 100                                                                              77 S  95 56  S                       1/2 + 1/2                                                                         100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 95 86                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              97  S                X-100  1/4 + 1/2                                                                         100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 85 68                                                                              S 100                                                                              100                                                                              AD 100                                                                              97 S  100                                                                              100 AD               +      1/2 + 1/2                                                                         100                                                                              97 S  100                                                                              100                                                                              AD 100                                                                              88                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100 AD               LASSO  1/4 + 1                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 88                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100 AD                      1/2 + 1                                                                           100                                                                              98 S  100                                                                              100                                                                              AD 98 95                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100 AD               X-100  1/4 + 1                                                                           98 100                                                                              A  100                                                                              100                                                                              AD 90 60                                                                              S 100                                                                              100                                                                              AD 100                                                                              97 S  100                                                                              96  S                +      1/2 + 1                                                                           100                                                                              82 S  100                                                                              100                                                                              AD 98 95                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 98 99  A                AMIBEN 1/4 + 2                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 80 72                                                                              S 100                                                                              100                                                                              AD 100                                                                              97 S  100                                                                              98  S                       1/2 + 2                                                                           100                                                                              94 S  100                                                                              100                                                                              AD 85 89                                                                              A 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              99  S                X-100  1/4 + 1/4                                                                         100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 60 20                                                                              S 100                                                                              100                                                                              AD 100                                                                              95 S  95 84  S                +      1/2 + 1/4                                                                         100                                                                              91 S  100                                                                              100                                                                              AD 85 70                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              99  S                PROWL  1/4 + 1/2                                                                         100                                                                              100                                                                              AD 95 100                                                                              A  40 20                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              96  S                       1/2 + 1/2                                                                         100                                                                              95 S  98 100                                                                              A  75 70                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              99  S                X-100  1/4 + 2                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              20                                                                              S 100                                                                              100                                                                              AD 100                                                                              87 S  65 80  A                +      1/2 + 2                                                                           100                                                                              88 S  100                                                                              100                                                                              AD 90 70                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 80 96  A                RAMROD 1/4 + 3                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 85 68                                                                              S 100                                                                              100                                                                              AD 100                                                                              96 S  80 96  A                       1/4 + 3                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 90 88                                                                              S 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 95 99  A                CONTROL                                                                              --  0  0  0  0  0  0  0  0 0 0  0     0  0                             __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________    Post-Emergence                                                                Application  PW       CB       AMG      SP      VL       YNS                  Treatment                                                                            Rate lb/A                                                                           O  E  R  O  E  R  O  E  R  O  E R     E  R  O E R                __________________________________________________________________________    X-100  1/4   70       80       75       20      100      80                          1/2   65       95       100      50      100      90                   ATRAZINE                                                                             1/4   100      100      100      40      100      20                          1/2   100      100      100      60      100      35                   X-100  1/4 + 1/4                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 55 52                                                                              S  100                                                                              100                                                                              AD 80                                                                              84 A               +      1/2 + 1/4                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 70 70                                                                              AD 100                                                                              100                                                                              AD 95                                                                              92 S               ATRAZINE                                                                             1/2 + 1/2                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 90 68                                                                              S  100                                                                              100                                                                              AD 90                                                                              87 A                      1/2 + 1/2                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              80                                                                              S  100                                                                              100                                                                              AD 90                                                                              94 A               CONTROL                                                                              --    0  0  0  0  0  0  0  0  0  0  0    0  0                          __________________________________________________________________________

                                      TABLE 5                                     __________________________________________________________________________    Post-Emergence                                                                Application  LCG      JG       WPM     FP       GG      SC                    Treatment                                                                            Rate lb/A                                                                           O  E  R  O  E  R  O  E  R O  E  R  O   E R O  E R                __________________________________________________________________________    X-100  1/4   100      100      95      75       70      45                           1/2   100      100      90      80       80      60                    ATRAZINE                                                                             1/4   85       25       35      20       65      20                           1/2   75       20       35      40       60      10                    X-100  1/4 + 1/4                                                                           100                                                                              100                                                                              AD 95 100                                                                              A  95 97 A 80 80 AD 70  90                                                                              A 25 56 A               +      1/2 + 1/4                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              94 S 60 84 A  90  93                                                                              A 60 68 S               ATRAZINE                                                                             1/2 + 1/2                                                                           100                                                                              100                                                                              AD 90 100                                                                              A  100                                                                              97 S 100                                                                              85 S  100 88                                                                              S 35 51 A                      1/2 + 1/2                                                                           100                                                                              100                                                                              AD 100                                                                              100                                                                              AD 100                                                                              94 S 75 88 A  100 92                                                                              S 40 64 A               CONTROL                                                                              --    0  0  0  0  0  0  0  0  0 0  0     0   0                         __________________________________________________________________________

                                      TABLE 6                                     __________________________________________________________________________    Post-Emergence                                                                Application  SA       RJG    YFT    GFT    CORN 55A                                                                            CORN 23A                     Treatment                                                                            Rate lb/A                                                                           O  E  R  O E R  O  E R O  E R O E R O E R                        __________________________________________________________________________    X-100  1/4   80       0      75     75     0     0                                   1/2   90       20     85     90     0     0                            ATRAZINE                                                                             1/4   100      0      65     70     0     0                                   1/2   95       0      65     75     0     0                            X-100  1/4 + 1/4                                                                           100                                                                              100                                                                              AD 0 0 AD 75 91                                                                              A 70 93                                                                              A 0 0   0 0                          +      1/2 + 1/4                                                                           95 100                                                                              A  10                                                                              20                                                                              A  100                                                                              95                                                                              S 100                                                                              97                                                                              S 0 0   0 0                          ATRAZINE                                                                             1/2 + 1/2                                                                           100                                                                              99 S  10                                                                              0 S  100                                                                              91                                                                              S 98 94                                                                              S 0 0   0 0                                 1/2 + 1/2                                                                           100                                                                              100                                                                              AD 0 20                                                                              A  98 95                                                                              S 95 98                                                                              A 0 0   0 0                          CONTROL                                                                              --    0  0  0  0 0 0  0  0 0 0  0   0 0                                __________________________________________________________________________

Application rates for the compositions of this invention will dependupon the weeds to be controlled and the degree of control desired. Ingeneral, the compositions of this invention are most efficientlyemployed at a rate of 0.01 to 50 pounds per acre (0.011 to 56 kilogramsper hectare) of the active ingredients, preferably 0.1 to 25 pounds peracre (0.11 to 28 kilograms per hectare).

The compositions of the present invention show synergistic activity asherbicides in controlling the growth of undesirable vegetation whenapplied to such vegetation in pre- or postemergence application. Thecompositions are generally embodied in formulations which contain inertor occasionally active ingredients or diluent carriers in addition tothe active compounds. Examples of such ingredients or carriers arewater, organic solvents, surface active agents, oil, water-in-oilemulsions, wetting agents, dispersing agents, and emulsifying agents.The herbicidal formulations generally take the form of wettable powders,solutions or emulsifiable concentrates.

Wettable powders are finely divided compositions comprising aparticulate carrier impregnated with the herbicidal compound andadditionally containing one or more surface active agents. The surfaceactive agent promotes rapid dispersion of the powder in aqueous mediumto form stable, sprayable suspensions. A wide variety of surface activeagents can be used, for example, long chain fatty alcohols and alkalimetal salts of the sulfates fatty alcohols, salts of sulfonic acid;esters of long chain fatty acids; and polyhydric alcohols, in which thealcohol groups are free, omega-substituted polyethylene glycols ofrelatively long chain length.

The herbicidal compositions can also be applied to the foilage in theform of a solution in a suitable solvent. Solvents frequently used inherbicidal formulations include kerosene, fuel oil, xylene, petroleumfractions with boiling ranges above xylene, and aromatic petroleumfractions rich in methylated naphthalenes.

The most preferred formulations are emulsifiable concentrations whichconsist of an oil solution of the herbicide along with an emulsifyingagent. Prior to use the concentrate is diluted with water to form asuspended emulsion of oil droplets. The emulsifiers used are usually amixture of anionic and nonionic surfactants. Other additives such asspreading agents and stickers can be included in the emulsifiableconcentrate.

The formulations described above can be applied to the vegetation soughtto be controlled in any conventional manner either before or after thevegetation has emerged from the soil. The vegetation can be in any stageof development after emergence, ranging from seedlings to fully grownplants. Application can be achieved by any conventional technique suchas the use of ground spraying equipment or aircraft-mounted sprayers.Various other application techniques will be apparent to one skilled inthe pesticide art.

What is claimed is:
 1. A synergistic herbicidal composition comprising amixture of:(a) a herbicidally effective amount of2-(2-chloro-4-methanesulfonylbenzoyl)-1,3-cyclohexanedione; and (b) aherbicidally effective amount of a compound selected from the groupconsisting of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine,3-amino-2,5-dichlorobenzoic acid, and 2-chloro-N-isopropylacetanilide,and mixtures thereof; at a weight ratio of (a) to (b) of from about 1:2to about 2:1.
 2. The composition of claim 1 wherein (b) is2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine.
 3. Thecomposition of claim 1 wherein (b) is 3-amino-2,5-dichlorobenzoic acid.4. The composition of claim 1 wherein (b) is2-chloro-N-isopropylacetanilide.
 5. A synergistic herbicidal compositioncomprising a mixture of:(a) a herbicidally effective amount of2-(2-chloro-4-methanesulfonylbenzoyl)-1,3-cyclohexanedione; (b) aherbicidally effective amount of a compound selected from the groupconsisting of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine,3-amino-2,5-dichlorobenzoic acid, and 2-chloro-N-isopropylacetanilide,and mixtures thereof; and (c) an inert diluent carrier, at a weightratio of (a) to (b) of from about 1:2 to about 2:1.
 6. The compositionof claim 5 wherein (b) is2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine.
 7. Thecomposition of claim 5 wherein (b) is 3-amino-2,5-dichlorobenzoic acid.8. The composition of claim 5 wherein (b) is2-chloro-N-isopropylacetanilide.
 9. A method of controlling undesirablevegetation which comprises the application of said vegetation of aherbicidal composition comprising(a) a herbicidally effective amount of2-(2-chloro-4-methanesulfonylbenzoyl)-1,3-cyclohexanedione; (b) aherbicidally effective amount of a compound selected from the groupconsisting of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine,3-amino-2,5-dichlorobenzoic acid, and 2-chloro-N-isopropylacetanilide,and mixtures thereof, at a weight ratio of (a) to (b) of from about 1:2to about 2:1.
 10. The method of claim 9 wherein (b) is2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine.
 11. The method ofclaim 9 wherein (b) is 3-amino-2,5-dichlorobenzoic acid.
 12. The methodof claim 9 wherein (b) is 2-chloro-N-isopropylacetanilide.